共查询到20条相似文献,搜索用时 15 毫秒
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5-Cyanoindazoles are conveniently prepared in two to three steps from commercially available 5-bromo-2-fluorobenzaldehyde. 相似文献
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Yu. Yu. Popelis É. É. Liepin'sh E. Ya. Lukevits 《Chemistry of Heterocyclic Compounds》1985,21(9):974-979
The 1H, 13C, and 15N NMR spectra of 15N-enriched 5-substituted furfural oximes were investigated. It was shown that the chemical shifts of the ring atoms and the oxime group correlate satisfactorily with the F and R substituent constants, whereas their sensitivity to the effect of the substituents is lower than in monosubstituted furan derivatives. The constants of spin-spin coupling between the ring protons and the oxime group were determined. An analysis of the 1H-1H spin-spin coupling constants (SSCC) on the basis of their stereospecificity indicates that the E isomers have primarily an s-trans conformation in polar dimethyl sulfoxide, whereas the Z isomers, on the other hand, have an s-cis conformation. The signs of the direct and geminal 13C-15N SSCC were determined for 5-trimethylsilylfurfural oxime.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1172–1177, September, 1985.The authors thank N. O. Saldabol, L. M. Ignatovich, and N. P. Erchak for providing us with the investigated compounds. 相似文献
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Xi Guang LIU Jing Ping WU Xiao Mei LIANG Dao Quan WANG* Key Laboratory of Pesticide Chemistry Application Technology College of Applied Chemistry China Agricultural University Beijing 《中国化学快报》2002,13(4)
The avermectins1 are a unique collection of naturally occurring macrocyclic lactones with broad spectrum of anthelmintic and insecticidal activities. Their remarkable biological activity and complex molecular architecture stimulated significant interest in the scientific community. Much research has been carried out on these compounds. Many derivatives of avermectin have much more bioactivities and have been commercially utilized2-5. Here we describe the synthesis of 5-deoxy-5-acyloxyimi… 相似文献
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Reaction of aryldichloroisocyanides 1a–e with sodium azide and a phase transfer agent has provided 5-chloro-1-aryl-1H-tetrazoles 2a–e in good yield. In particular, the widely-used intermediate, 5-chloro-1-phenyl-1H-tetrazole 2a, can be produced conveniently and safely in yields approaching 100%. 相似文献
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R. S. Baltrushis Z. -I. G. Beresnevichyus I. M. Vizgaitis Yu. V. Gatilov 《Chemistry of Heterocyclic Compounds》1981,17(12):1226-1231
The reaction of aromatic amines with maleic acid or its diethyl ester with subsequent hydrolysis gave N-arylaspartic acids, which were converted to 1-aryl- and 1-aryl-2-thio-5-carboxymethylhydantoins by the action of urea, cyanates, or thiocyanates in an acidic medium. Esterification of the acid products with methanol gave the corresponding carbomethoxymethylhydantoins, which were converted by reduction to tetrahydroimidazole derivatives and by acetylation to acetyl derivatives. Alkylation of the carboxymethylhydantoins with dimethyl sulfate gave 3-methyl derivatives of hydantoins, while alkylation with formaldehyde gave 3-hydroxymethyl derivatives of hydantoins. Data from the x-ray diffraction analysis of 1-phenyl-2-thio-5-carbomethoxymethylhydantoin are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1669–1674, December, 1981. 相似文献
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The infrared and Raman spectra of 1-phenyl-5-mercaptotetrazole (PMT) and 1-phenyl-5-mercaptotetrazole sodium salt in the solid state and in solution have been measured. Detailed vibrational assignments of PMT and 1-phenyl-5-mercaptotetrazolate (PMTA) have been performed. In order to give a firmer basis to the interpretation of the vibrational spectra, harmonic wavenumbers of PMT and PMTA have been calculated by means of MP2 and DFT/BPW91 calculations. The DFT calculations provide a satisfactory agreement between the calculated and observed wavenumbers without using scaling factors. Experimental evidence shows that PMT is present in the thione tautomer both in the solid state and in solution of polar solvents. 相似文献
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M. Bolte 《Acta Crystallographica. Section C, Structural Chemistry》1997,53(12):IUC9700027-IUC9700027
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Relativistic multiconfiguration Dirac-Fock (MCDF) transition energies and oscillator strengths are determined for both the spin-allowed 5s
2
1
S
0-5s5p
1
P
1 and the spin-forbidden 5s
2
1
S
0-5s5p
3
P
1 transitions in the strontium isoelectronic sequence. The modest relativistic configuration mixing to represent intravalence correlation is combined with a polarization model to account for valence-core electron correlations. The multiconfiguration Dirac-Fock calculations are performed in an average level scheme; however for neutral strontium and singly ionized yttrium a thorough comparison of the average and the optimal level schemes is presented. The average level scheme, though less accurate for the neutral end of the sequence, avoids the convergence problems encountered for highly ionized systems, where the 5s 5p
3
P
1,1
P
1 states are raised owing to the collapse of the 4d
3/2, 5/2 spin-orbitals in the isoelectronic sequence and, thus, allows us to extend our study to multiple charged ions (throughW
36+). Since for such systems there is practically no difference between the results of the average and the optimal level versions of MCDF calculations, we believe that our average level predictions of ionization energies and oscillator strengths for states with total angular numberJ=0 andJ=1 are of comparable quality to those that could be obtained with an optimal level scheme.This study was supported by the Pedagogical Academy of Kraków Statutory Activity Grant No BS-29/91 相似文献